FMS monitors the diagonal pivots during the factoring process.
You may set tolerances based on machine architecture for printing warning messages when
a pivot becomes small, or when a pivot is considered zero.
You may also provide a subroutine you write to handle
exceptions when a zero pivot is encountered.
FMS includes utilities for computing Eigenvalues using
subspace iteration.
This option allows you to interrupt the factoring and solving process at the bottom of
the matrix and extract a reduced system of equations.
You may use this for design optimization, nonlinear analyais,
superelements and solving nonsymmetric systems when only a few of the matrix terms are
nonsymmetric.
You select this option with the
NEQSUB Parameter.
This option allows you to reuse part of the matrix factors when only some of the matrix
terms have changed. You select this option with the
LOWASM Parameter.
This option transforms a matrix stored as nonsymmetric into a symmetric matrix by
averaging the off-diagonal terms. You select this option with the
LUOK Parameter.
These algorithms reduce the number of floating point operations for BLOCK and SLAB matrices.
They are selected by the
IALGOR Parameter